Laminated tape structures including a central layer of polymeric film or foam with layers of adhesive on its opposite major surfaces (e.g., the tape structures sold under the trade designations "Wallsaver Removable poster tape", "3M Automotive attachment Tape", or "3M Acrylic Foam Tape" by Minnesota Mining and Manufacturing Company, St. Paul, Minn.) have been used to bond the opposed surfaces of two objects together, such as to bond a wall hanging such as a poster, plaque, or a picture to a wall. When such a tape structure in which the adhesive is a high tack pressure sensitive adhesive (e.g., the "3M Acrylic Foam Tape" mentioned above) is used for that purpose, it is often difficult to later separate the objects. The tape structure is positioned in a very narrow area between the objects where it is not readily accessible, particularly when the tape structure is between a rigid wall hanging and a wall. Typically, an attempt is made to either slice the tape structure in half between its outer surfaces with a knife or similar implement poked between the objects, or one object (e.g., a wall hanging) is twisted on or pulled from the other object (e.g., a wall), often resulting in damage to one or both of the objects.
Laminated structures are described in U.S. Pat. No. 4,310,137 (Frye) that include outer attachment layers having opposite major surfaces defined by pressure sensitive adhesive that can be adhered to the opposed surfaces of closely spaced objects so that the laminated structures support one object from the other, and a separable layer of non-fusible porous material such as tissue paper between the outer attachment layers that can be separated by an outward exertion on one of the outer attachment layers away from the other.
Attachment strips having opposite major surfaces at least partially defined by pressure sensitive adhesive have been developed that can be used to bond objects together, and can subsequently be stretched by pulling on tab portions at ends of the attachment strips to cleanly separate the adhesive bonds between the attachment strips and the objects they had previously joined (e.g., see U.S. Pat. Nos. 5,409,189 (Luhmann) and 5,516,581 (Kreckel et al), and U.S. patent application Ser. No. 08/308,937 (Bries et al)). While such stretch releasable attachment strips work well, the tab portion at the end of such a attachment strip joining two or more objects should be positioned where it can be engaged by a person who later wishes to separate the objects. One of the objects can be specially made with a removable portion that covers that tab portion (see U.S. Pat. No. 5,507,464, Hamerski et al), or, if one of the objects is flexible, that flexible object may be bent to afford access to that tab portion. In many instances where rigid objects are joined, however, it may be necessary to allow the tab portion to project from between the joined objects to afford such engagement with that tab portion to remove the stretchable attachment strip from between the objects. Such a projecting tab portion can be aesthetically objectionable.
German Patent Publication DE 43 39 604 dated May 24, 1995, describes a tape structure that can be used to bond together the opposed surfaces of objects including rigid objects with no portion of the tape structure projecting from between the objects, and which subsequently affords separation of the objects by moving one of the objects relative to the other. That tape structure is described as an adhesive tape for separable adhesive joints made from a double-sided adhesive tape which has adhesive areas on opposing sides at an offset which are not adherent, whereby the non adherent areas do not, or only slightly overlap, and which allow the adhesive joint made with them to be separated by pulling apart the non-adhesive areas, particularly by pulling in the direction of the adhesive plane.
U.S. patent application Ser. No. 08/746,351 filed Nov. 8, 1996, discloses a tape structure that can be used to bond together the opposed surfaces of objects including rigid objects (e.g., bond a plaque or framed picture to a wall) with no portion of the tape structure projecting from between the objects, and which subsequently affords easy separation of the objects without damage to either of them. That tape structure comprises an internally separable layer having opposite major anchor surfaces. The anchor surfaces are adapted to be bonded to the opposed surfaces of objects (e.g., by layers of pressure sensitive or other types of adhesive on the anchor surfaces or by other means such as heat fusion or the use of stretch releasable attachment strips as is described below). The internally separable layer has an internal static shear strength in a direction parallel to its anchor surfaces that is adapted to support one of the objects to which it is attached from the other with its anchor surfaces vertically disposed (e.g., preferably has a static shear strength parallel to its anchor surfaces that is about equal to or exceeds the maximum static shear strength that pressure sensitive adhesive will develop with normal surfaces to which it can be adhered), and has an internal dynamic tensile strength in a direction generally normal to its anchor surfaces that will afford internal separation of the separable layer by pulling apart the objects it has joined without damaging the surfaces of those objects. In an embodiment of that laminate adapted to be easily and cleanly removed from one or both of the objects it attaches together, the laminate comprises one or two stretch releasable attachment strips each having an outer surface defined by pressure sensitive adhesive that can be adhered to an object and being stretchable by being manually pulled at an end tab portion to release adhesive engagement of its outer surface to an object to which it has been adhered.